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bassdude404 09-25-2006 04:28 PM

AC conversion
 
I've got an AC question. My '81 caddy hearse has the old R-12 ac system. Can I buy the conversion kit and just fill it with R-134, Or do I have to evacuate the system of all the R-12 first?? I'm wanting to get it working next spring. I'm used to AC in my semi, now I gotta get it working in my 4-wheeler... :sweat: :sweat:

nitro_baller4692 09-25-2006 05:28 PM

you have to vacumm it all out.replace the seals because the r-134a and r-12 use different oils and seals.that is if you want it to last.

75gmck25 09-25-2006 06:21 PM

Why did the AC quit working? If was just a small leak, then you might want to evacuate, repair the leaking component, replace the accumulator, and refill with R12. R12 is more expensive than R134a, but its relatively cheap compared to the cost of AC parts and labor.

Bruce

Mustangsaly 09-25-2006 09:46 PM

I had a refrigerant guy here charging my chest freezer. the freezer had R12 in it, (the chest freezer was built in 1985) he had to empty the freezers R12 (or just does cause you never know what else someone has put/mixed in a system, even if the refrigerants are compatible or not), and he vacuumed it down and put 416A refrigerant in it. he said 416A is compatible with R12 & R12 systems, but he don't like to mix refrigerants, compatible or not. because he don't know what the guy B4 or after him has done or mixed. (you have to have a license to buy 416A) but he said 416A has less head pressure than R134A and cools better than R134A especially in 100 degree days, it cools like the R12 refrigerant in the R12 systems. as he has used it in his dads tractors/combines and P/Us. 416A is not expensive like R12, you just need a refrigeration guy not a auto a/c man. he said auto a/c shops use R134 cause the auto industry recommends it and the auto a/c shops don't need to know the different refrigerants or refrigeration beyond R134.

I have two R12 systems left, and I will try 416A B4 retrofiring a R12 system to a R134a system. (R134a does not cool the best in a R12 system, even with the right components replaced) R134A is not a direct replacement for R12. with R134a into a R12 system you need to empty the R12 & change some R12 a/c system components and flush the R12 system & vacuum the system down B4 charging with R134a .




Mustangsaly

75gmck25 09-25-2006 10:45 PM

In general, its a lot simpler if you stick with either R-12 or R-134a, because most AC places can recover and recharge both of them. R416A may work fine, but you will need to be prepared to do everything with your own equipment.

I checked an online store for the price of 30 lb cylinders of refrigerant:
R-134a - $199
R-416A - $295
R-12 - $577

This puts the cost of bulk R-134a at about $7/lb and bulk R-12 at about $21/lb. Since most systems won't need more than about 3-4 lbs of refrigerant, either choice is probably within a reasonable budget. However, I've found that most repair places don't stock R-12 anymore and may not be maintaining their R-12 recharge machine, since nearly all their business is with R-134a.

Bruce

nitro_baller4692 09-26-2006 06:00 AM

i have 5 cases of r-12 in one pound cans did not cost me nothen :evil:

Mustangsaly 09-26-2006 08:11 AM

Quote:

Originally Posted by 75gmck25
I checked an online store for the price of 30 lb cylinders of refrigerant:
R-134a - $199
R-416A - $295
R-12 - $577

This puts the cost of bulk R-134a at about $7/lb and bulk R-12 at about $21/lb. Since most systems won't need more than about 3-4 lbs of refrigerant, either choice is probably within a reasonable budget. However, I've found that most repair places don't stock R-12 anymore and may not be maintaining their R-12 recharge machine, since nearly all their business is with R-134a.
Bruce

true
Quote:

Originally Posted by 75gmck25
In general, its a lot simpler if you stick with either R-12 or R-134a, because most AC places can recover and recharge both of them. R416A may work fine, but you will need to be prepared to do everything with your own equipment.



heck theres 2 refrigeration technicians / 1 and 2 man shops in my small town of 750 people. so finding a refrigerant technician / man should not be hard.

but 416a is more compatible with the R12 systems with out the retrofitting of R12 a/c systems and components, and another plus is 416a cools like R12. 8 out of 10 people that retrofit a R12 system over to a R134 system are not happy with the cooling. and retrofitting a R12 system isn't cheap. yes you would need a refrigeration man, Not a automotive a/c technician for any a/c work done on a system with 416a in it. (a system with 416a in it should be labeled clearly with a 416a refrigerant label for technicians to see) but a refrigeration man will know a/c systems better than the run of the mill R134 a/c technician will. I'm not putting down any R134a automotive a/c technician, but there just not trained like a refrigeration technician or do they deal with all the systems a refrigeration man does. the refrigeration man that was here said he carries 9 different refrigerants on his truck.

I have some R12 12oz cans to. my dad has a buddie that sells 10 cars a week to a couple Hispanic's/Mexicans that take the cars to Mexico and they can and will/do bring all the R12 12oz cans from mexico that my dads buddie wants. my dad is sitting on 4 or 5 cases too. he don't offer any R12 up, but he keeps me going on a as needed request only.

the refrigeration man that was here said that he thinks in 3 or 4 yrs all refrigerant in containers under 1lb will be sold over the counter w/out a license. except probably the R12 refrigerant .

you and others might not like the 416a refrigerant idea as a R12 replacement, but I do and just thought others might too. plus its just some more information on refrigeration and other refrigerant out there. he said theres a couple other refrigerant (but I forget the name/number of it) thats compatible with R12 system with out retrofitting the R12 systems, but he likes and has had best luck with the 416a refrigerant in all R12 systems and in automotive R12 systems.



Mustangsaly

sbchevfreak 09-26-2006 09:10 PM

AFAIK, after 2001, it became illeagal to possess or install R12. R416 and R414 are acceptable repacements, however I have had two compressors fail (auto application) due to oil circulation issues. I'm not sure what the laws are in the USA, but here in Canada I use Duracool 12a. It is a hydrocarbon blend, and is a direct replacement.

Here is one discussion on the subject.

Mustangsaly 09-27-2006 10:24 AM

Quote:

Originally Posted by sbchevfreak
R416 and R414 are acceptable repacements, however I have had two compressors fail (auto application) due to oil circulation issues.




you think this was due to the 416a or 414a refrigerant ? you like Duracool better than 416a or 414a ?






Mustangsaly

sbchevfreak 09-27-2006 09:07 PM

I installed two new compressors, and used R414 as an R12 replacement. Both compressors (in a row, on the same vehicle) failed within 24 hours of being installed. When The third compressor arrived, the only thing done differently was that the system was charged with R134A, and the compressor is still in service 4 years later.


I do prefer Duracool as an R12 replacement, and I have a significant amount of experience with it. I have used sveral other products, as well, but the Duracool seems to work the best. I prefer it to RedTek for the fact that is has an unpleasant odour, so if you have a leak, you won't confuse it for anything else. I runs lower head pressures than 134a, and needs less system charge (by weight) than both R12 & R134a. I have serviced hundreds of sytems, and have had none fail or operate poorly due to the refrigerant.


IMO, retrofitting to R134a will leave you dissapointed with your systems performance. After testing several retrofits, and brushing up on some pressure/temperature charts, I have drawn the conclusion that due to it's lower efficiency, R134a was not a good choice for installation in an R12 system. The condenser and evaporator do not have the physical size to cope with the higher pressures produced by R134a, and results are poor vent temperatures. Newer vehicles have engineered the A/C system components to compensate for this, and they work well.

65Stanger 09-28-2006 03:19 AM

I've got a '73 benz AC system to re-install. It's all put in, and I think they originally used R14... I just need to connect the wire to it, and fill it up with refridgerant. Anyone know what I should use in this system? It doesn't leak or anything, but we had to pull it out to rewire and change the alternator. Thanks.


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